On the number of limit cycles bifurcating from a non-global degenerated center

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Distribution center consolidation games

We study the location-inventory model as introduced by Teo et al. (2001) to analyze the impact of consolidation of distribution centers on facility and inventory costs. We extend their result on profitability of consolidation. We associate a cooperative game with each location-inventory situation and prove that this game has a non-empty core for identical and independent demand processes. This illustrates that consolidation does not only lower joint costs (which was shown by Teo et al. (2001)), but it allows for a stable division of the minimal costs as well.

Resum de la tasca realitzada al Center Biomedical Engineering (CBE) del Massachussets Institute of Technology (MIT). Juliol-Agost 2005

Estudi elaborat a partir d’una estada al Center Biomedical Engineering (CBE) del Massachussets Institute of Technology (MIT), durant els mesos de juliol i agost del 2005. S’investiga una metodologia amb l’objectiu d’obtenir biomaterials que puguin actuar de bastida en la interfície os/cartílag, afavorint la diferenciació i creixement cel·lular de cartílag ossificat que pugui actuar d’unió entre l’articulació i l’os. S’experimenta una metodologia per a establir quins són els péptids afavoridors de la formació de teixit ossi utilitzats en materials d’hidroxiapatita. Es conclou que la tecnologia desenvolupada permet disposar d’una plataforma per assajar l’estudi del signaling sobre cèl·lules embrionàries, que permeti desenvolupar materials amb més capacitat diferenciadora.

The third order Melnikov function of a quadratic center under quadratic perturbation

We study quadratic perturbations of the integrable system (1+x)dH; where H =(x²+y²)=2: We prove that the first three Melnikov functions associated to the perturbed system give rise at most to three limit cycles.

Contribuição ao estudo de Histoplasma capsulatum (Darling, 1906)

Usando o meio de amônio-sulfato-glicose, conseguimos que oito amostras estéreis de Histoplasma capsulatum voltassem a produzir estalagmosporos.

The entropy conjecture for partially hyperbolic diffeomorphisms with 1-D center

We prove that if f is a partially hyperbolic diffeomorphism on the compact manifold M with one dimensional center bundle, then the logarithm of the spectral radius of the map induced by f on the real homology groups of M is smaller or equal to the topological entropy of f. This is a particular case of the Shub's entropy conjecture, which claims that the same conclusion should be true for any C1 map on any compact manifold.

Applying RADIC in Open MPI: the methodology used to implement RADIC over a Message Passing Library

Fault tolerance has become a major issue for computer and software engineers because the occurrence of faults increases the cost of using a parallel computer. RADIC is the fault tolerance architecture for message passing systems which is transparent, decentralized, flexible and scalable. This master thesis presents the methodology used to implement the RADIC architecture over Open MPI, a well-know large-used message passing library. This implementation kept the RADIC architecture characteristics. In order to validate the implementation we have executed a synthetic ping program, besides, to evaluate the implementation performance we have used the NAS Parallel Benchmarks. The results prove that the RADIC architecture performance depends on the communication pattern of the parallel application which is running. Furthermore, our implementation proves that the RADIC architecture could be implemented over an existent message passing library.

Memòria de recerca: paral·lelització dels diccionaris de la Standard Template Library de C++

Estudi elaborat a partir d’una estada a la Universität Karlsruhe entre gener i maig del 2007. Les biblioteques d’estructures de dades defineixen interfícies i implementen algorismes i estructures de dades fonamentals. Un exemple n’és la Satandard Template Library (STL ), que forma part del llenguatge de programació C++. En el marc d’una tesi, s’està treballant per obtenir implementacions més eficients i/o versàtils d’alguns components de la STL. Per a fer-ho s’utilitzen tècniques de la enginyeria d’algorismes. En particular, s’integra el coneixement de la comunitat algorítmica i es té en consideració la tecnologia existent. L’acció durant l’estada s’ha emmarcat en el desenvolupament la Multi Core STL (MCSTL ). La MCSTL és una implementació paral•lela de la STL per a màquines multi-core. Les màquines multi-core són actualment l’únic tipus de màquina disponible al mercat. Per tant, tot i que el paral•lelisme obtingut no sigui òptim, és preferible a tenir els processadors esperant, ja que , la tendència és que el nombre de processadors per computador augmenti.

Seizures after single-agent overdose with pharmaceutical drugs: Analysis of cases reported to a poison center.

Abstract Context. Seizures during intoxications with pharmaceuticals are a well-known complication. However, only a few studies report on drugs commonly involved and calculate the seizure potential of these drugs. Objectives. To identify the pharmaceutical drugs most commonly associated with seizures after single-agent overdose, the seizure potential of these pharmaceuticals, the age-distribution of the cases with seizures and the ingested doses. Methods. A retrospective review of acute single-agent exposures to pharmaceuticals reported to the Swiss Toxicological Information Centre (STIC) between January 1997 and December 2010 was conducted. Exposures which resulted in at least one seizure were identified. The seizure potential of a pharmaceutical was calculated by dividing the number of cases with seizures by the number of all cases recorded with that pharmaceutical. Data were analyzed using descriptive statistics. Results. We identified 15,441 single-agent exposures. Seizures occurred in 313 cases. The most prevalent pharmaceuticals were mefenamic acid (51 of the 313 cases), citalopram (34), trimipramine (27), venlafaxine (23), tramadol (15), diphenhydramine (14), amitriptyline (12), carbamazepine (11), maprotiline (10), and quetiapine (10). Antidepressants were involved in 136 cases. Drugs with a high seizure potential were bupropion (31.6%, seizures in 6 of 19 cases, 95% CI: 15.4-50.0%), maprotiline (17.5%, 10/57, 95% CI: 9.8-29.4%), venlafaxine (13.7%, 23/168, 95% CI: 9.3-19.7%), citalopram (13.1%, 34/259, 95% CI: 9.5-17.8%), and mefenamic acid (10.9%, 51/470, 95% CI: 8.4-14.0%). In adolescents (15-19y/o) 23.9% (95% CI: 17.6-31.7%) of the cases involving mefenamic acid resulted in seizures, but only 5.7% (95% CI: 3.3-9.7%) in adults (≥ 20y/o; p < 0.001). For citalopram these numbers were 22.0% (95% CI: 12.8-35.2%) and 10.9% (95% CI: 7.1-16.4%), respectively (p = 0.058). The probability of seizures with mefenamic acid, citalopram, trimipramine, and venlafaxine increased as the ingested dose increased. Conclusions. Antidepressants were frequently associated with seizures in overdose, but other pharmaceuticals, as mefenamic acid, were also associated with seizures in a considerable number of cases. Bupropion was the pharmaceutical with the highest seizure potential even if overdose with bupropion was uncommon in our sample. Adolescents might be more susceptible to seizures after mefenamic acid overdose than adults. "Part of this work is already published as a conference abstract for the XXXIV International Congress of the European Association of Poisons Centres and Clinical Toxicologists (EAPCCT) 27-30 May 2014, Brussels, Belgium." Abstract 8, Clin Toxicol 2014;52(4):298.

Definició i estudi de viabilitat d'un "support center" funcional en una empresa farmacèutica

Este proyecto comprende dos componentes centrales. Estos son, definir la situación actual sobre el soporte funcional en las aplicaciones y proponer soluciones para una mejora de los servicios. Durante la descripción de la situación actual se han ido encontrando problemas en el soporte, y se proponen soluciones. Se han llegado a proponer 3 modelos distintos de los cuales se ha elegido uno, el cual supone una importante mejora en el servicio.